Mafless?
05-09-2006, 11:14 AM
#2
http://www.hptuners.com/pr-1_7_0.html
this gives a little insite into it...98's can be a pita since they have 2 ve tables & the one you use when in SD has much less resolution in your case. Basically it can give you better drivability with larger cams and can, theoretically, give you more hp since you can completely rid yourself of the maf...99% of tunes I do end up not running SD all the time though.
this gives a little insite into it...98's can be a pita since they have 2 ve tables & the one you use when in SD has much less resolution in your case. Basically it can give you better drivability with larger cams and can, theoretically, give you more hp since you can completely rid yourself of the maf...99% of tunes I do end up not running SD all the time though.
05-09-2006, 11:18 AM
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honestly unless you plan on pushin 20lbs of boost OR REALLY BUILDING UP YOUR MOTOR stick with the MAF....dial in your VE table in Open loop
dial in your MAF and watch your LTFT's go down to around +4 -4
and you will be able to tell your car will run a little better....also WOT log the MAF frequencies and get your WOT fuel where you want it
..see my sig...and I'm soon going 5lbs of STS power with the MAF... car runs great
the MAF is your friend
"more hp mafless" measures the ability of the tuner MAFless with dialing in the VE table...which with varying temps depending on where you live can change your actual AFR a bit. Tune with the MAF and your car will match the same power.....no matter the temp or barometric pressure or anything...the MAF is a good thing
dial in your MAF and watch your LTFT's go down to around +4 -4
and you will be able to tell your car will run a little better....also WOT log the MAF frequencies and get your WOT fuel where you want it
..see my sig...and I'm soon going 5lbs of STS power with the MAF... car runs great
the MAF is your friend
"more hp mafless" measures the ability of the tuner MAFless with dialing in the VE table...which with varying temps depending on where you live can change your actual AFR a bit. Tune with the MAF and your car will match the same power.....no matter the temp or barometric pressure or anything...the MAF is a good thing
05-09-2006, 11:27 AM
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The reason I am asking is b/c I had a big cam put in a couple of month ago, the maf went bad(had a hesitation off idle to 1500rpm) Replaced with new maf/ descreened it fixed it for three weeks and now it's starting to happen again, why? i don't want to keep dumping money into mafs for no reason. Has to be an explanation for why this is happening? I never had a problem with stock cam and descreened maf, air filter is 11months old(kn) not oiled yet.
05-09-2006, 11:53 AM
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An extra expensive sensor that "flakes out" often is not what I'd call " my friend".
A good tuner (with added work) can adjust the MAF table until equal power (to a SD tune) is achieved on a dyno,
but the SD tune will run faster on the track still.
The biggest difference between MAF and SD operation is the difference between transitional and steady-state fueling.
You can imagine a difference like this: With the same TPS, the intake density will sometimes increase, decrease, or stay the same as the engine speed increases. With the MAF, the MAF output allways goes up as engine speed increases.
Fuel-trims or not, this is a source of inconsistancy in the MAF tune, and it has its biggest downside during transitions.
A good tuner (with added work) can adjust the MAF table until equal power (to a SD tune) is achieved on a dyno,
but the SD tune will run faster on the track still.
The biggest difference between MAF and SD operation is the difference between transitional and steady-state fueling.
You can imagine a difference like this: With the same TPS, the intake density will sometimes increase, decrease, or stay the same as the engine speed increases. With the MAF, the MAF output allways goes up as engine speed increases.
Fuel-trims or not, this is a source of inconsistancy in the MAF tune, and it has its biggest downside during transitions.
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05-09-2006, 11:55 AM
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Originally Posted by 98camaroLS1M6
I can't just take the maf off and run it can I, doesn't the car have to be tuned for it? Don't want to damage anything.
You will need to change the tune for SD for the long-term though.
05-11-2006, 12:27 PM
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Originally Posted by white2001s10
An extra expensive sensor that "flakes out" often is not what I'd call " my friend".
A good tuner (with added work) can adjust the MAF table until equal power (to a SD tune) is achieved on a dyno,
but the SD tune will run faster on the track still.
The biggest difference between MAF and SD operation is the difference between transitional and steady-state fueling.
You can imagine a difference like this: With the same TPS, the intake density will sometimes increase, decrease, or stay the same as the engine speed increases. With the MAF, the MAF output allways goes up as engine speed increases.
Fuel-trims or not, this is a source of inconsistancy in the MAF tune, and it has its biggest downside during transitions.
A good tuner (with added work) can adjust the MAF table until equal power (to a SD tune) is achieved on a dyno,
but the SD tune will run faster on the track still.
The biggest difference between MAF and SD operation is the difference between transitional and steady-state fueling.
You can imagine a difference like this: With the same TPS, the intake density will sometimes increase, decrease, or stay the same as the engine speed increases. With the MAF, the MAF output allways goes up as engine speed increases.
Fuel-trims or not, this is a source of inconsistancy in the MAF tune, and it has its biggest downside during transitions.
But, for some reason, with MAF enabled, my LTFTs go into four distinct QUADRANTS. And I cannot adjust the MAF frequencies to make my LTFTs the same with and without the MAF.
See the last few posts here..... http://www.hptuners.com/forum/showthread.php?t=5564
05-11-2006, 02:55 PM
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Originally Posted by silverTA2002
This probably explains why my throttle response seems way slower with the MAF enabled.
But, for some reason, with MAF enabled, my LTFTs go into four distinct QUADRANTS. And I cannot adjust the MAF frequencies to make my LTFTs the same with and without the MAF.
See the last few posts here..... http://www.hptuners.com/forum/showthread.php?t=5564
But, for some reason, with MAF enabled, my LTFTs go into four distinct QUADRANTS. And I cannot adjust the MAF frequencies to make my LTFTs the same with and without the MAF.
See the last few posts here..... http://www.hptuners.com/forum/showthread.php?t=5564
Yeah you are experiencing the big PITA that is the MAF.
Your lack of throttle response could be one of a few things.
Your instant fuel delivery may be quite different when running on the MAF. You may just be experiencing the MAF-delay. Another possibility is that you're running in a different load section of your timing table with the MAF hooked up.
You can compare your pulsewidths & spark advance on your scans with & without the MAF and especially look close around throttle transitions. You should be able to see what is different there.
I have a friend named Charlie Trifari that races there at Desoto. You don't happen to know him do you?
05-11-2006, 09:10 PM
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Originally Posted by white2001s10
I read your other post just now.
Yeah you are experiencing the big PITA that is the MAF.
Your lack of throttle response could be one of a few things.
Your instant fuel delivery may be quite different when running on the MAF. You may just be experiencing the MAF-delay. Another possibility is that you're running in a different load section of your timing table with the MAF hooked up.
You can compare your pulsewidths & spark advance on your scans with & without the MAF and especially look close around throttle transitions. You should be able to see what is different there.
I have a friend named Charlie Trifari that races there at Desoto. You don't happen to know him do you?
Yeah you are experiencing the big PITA that is the MAF.
Your lack of throttle response could be one of a few things.
Your instant fuel delivery may be quite different when running on the MAF. You may just be experiencing the MAF-delay. Another possibility is that you're running in a different load section of your timing table with the MAF hooked up.
You can compare your pulsewidths & spark advance on your scans with & without the MAF and especially look close around throttle transitions. You should be able to see what is different there.
I have a friend named Charlie Trifari that races there at Desoto. You don't happen to know him do you?
As far as timing goes, I see to be hitting the exact same cells with and without the MAF.
The difference I'm feeling seems about equivalent to 30 tq (at mid throttle). It's quite significant.
I really wanted to keep the MAF. But, the way I'm looking at it now...... If it makes me slower, what good does it do me?
I could see how at FULL throttle, a maf and mafless tune would be the same (just tune for the same a/f ratio). But at part throttle, it seems to be messing up my world.
05-12-2006, 03:47 AM
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The MAF restricts airflow. Take a look at it.
Why do you want this, when you can get more power and better throttle response with SD?
Answer: You dont.
Its there to put a plaster on the variations in engines and cars from the factory. It allows minor changes to be handled better than SD mode. But if you are tuning your own car you will be able to tune for these changes much better than the MAF.
Do yourself and your car a favour and bin the evil sod.
Why do you want this, when you can get more power and better throttle response with SD?
Answer: You dont.
Its there to put a plaster on the variations in engines and cars from the factory. It allows minor changes to be handled better than SD mode. But if you are tuning your own car you will be able to tune for these changes much better than the MAF.
Do yourself and your car a favour and bin the evil sod.